Light emitting diodes (LEDs) are manufactured by forming active regions on a substrate and by depositing various conductive and semiconductive layers on the substrate. The radiative recombination of electron-hole pairs can be used for the generation of electromagnetic radiation by the electric current in a p-n junction. In a forward-biased p-n junction fabricated from a direct band gap material, such as GaAs or GaN, the recombination of the electron-hole pairs injected into the depletion region causes the emission of electromagnetic radiation. The electromagnetic radiation may be in the visible range or may be in a non-visible range. Different colors of LEDs may be created by using materials with different band gaps. Further, an LED with electromagnetic radiation emitting in a non-visible range may direct the non-visible light towards a phosphor lens or a like material type. When the non-visible light is absorbed by the phosphor, the phosphor emits a visible light.
LEDs are typically manufactured on a substrate such as a sapphire (Al2O3) wafer. However, growing a GaN film on a sapphire substrate often results in crystal defects and cracks, due to the significant differences in the thermal expansion rate and the lattice constant between the GaN film and the substrate.
Multiple LEDs are typically formed on a single sapphire substrate and then diced or separated from each other. Often the dicing process includes a laser process and polishing. Unfortunately, the process of dicing the wafers to free individual LEDs may expose the LEDs to stress that may be harmful to the LED structures. The LEDs exposed to stress may crack, break, or manifest other damage.